Elephant Workers can build stuff slightly faster than a worker can. Note that Mule Oxen and elephant Workers all work at the same speed, which is faster than a Worker (or Gatherer).
As a city grows it can have more World Wonders (and national wonders). Thus bigger the cities the more wonders you can have. Note that in custom settings under "Unlimited Wonders" you can turn this feature off and have as many wonders as you want in a city.
Hmm. I don't know. Sounds like a possible bug. You should post that with a saved game if possible in the bugs section.
Thank you. And welcome to C2C. Let us know if you have any more questions. We would be happy to answer them.
Really thanks!
